The impact and penetration process of a cubic intruder on granular bed is simulated by means of Distinct Element Method (DEM) using PFC commercial code. The excavation stage of cratering is represented by numerical simulation, and the simulated size and penetration depth of the cubic intruder are consistent with experiments. The configurational temperatures are calculated from overlaps of particles, and the translational granular temperatures are calculated from translational velocities of particles. The generalized granular temperature is proposed to show the relation between the fluctuation translational velocity and the fluctuation velocity of deformation of particles. The major finding of this study is the configurational temperature and translational granular temperatures increase rapidly, reach maximum, and then decrease at the impact and penetration process of the intruder. The variations of energy dissipation are analyzed on the basis of generalized granular temperature in the impact and penetration process of the intruder through the granular bed. (C) 2016 Elsevier B.V. All rights reserved.